/*
 * Copyright 2018 Meituan Dianping. All rights reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.meituan.dorado.rpc.handler.filter;

import com.meituan.dorado.common.Role;
import com.meituan.dorado.common.extension.SPI;
import com.meituan.dorado.rpc.meta.RpcInvocation;
import com.meituan.dorado.rpc.meta.RpcResult;

/**
 * 过滤器接口, 业务可自行实现
 *
 * 注意：同一个Filter重复添加无效, 只执行一次
 */
@SPI
public interface Filter extends Role {

    /**
     * 值越大 优先级越高, 接口调用前最先执行
     */
    int getPriority();

    RpcResult filter(RpcInvocation invocation, FilterHandler nextHandler) throws Throwable;
}
